First of all, only 15 or so religions in Canada? We have Hindus, Sikhs, Buddhists, Confucianists, Protestants of all stripes, Catholics, Mormons, Muslims, various shades of religions of our native populations, and doubtless many more, so the writer must achieved that number through very broad clumpings of groups that might well offend those within the groups.

Second, it seems likely to me that religions served a sanitary purpose in many ways, as well as to differentiate a people from their neighbors. This principle is fairly well recognized among Christian/Jewish religious scholars, who have opined that a distinctive set of practices--such as keeping kosher, avoiding pork, and other hygienic and cultural practices helped develop both a strong group identity and ensure its cultural and biological continuity.

Third, however, many intellectual reactions to religion seem to avoid the possibility of a personal satisfaction to the individual. For the totality of humankind buffeted by life, it helps to have a way to regularly turn your mind and self to hope, to beauty, to an inner place of peace.

In fact, prayer, meditation, yoga, simple focused breathing exercises, and numerous other "spiritual'' or religious practices worldwide over the centuries have helped people relax and de-stress. Dr. Herbert Benson's studies on what he called ''the relaxation response'' were published over 25 years ago, in which he looked at a number of similar practices across cultures and found they lowered the blood pressure and heart rate of practitioners. Their health improved in other ways as well. His studies were quantitative, not anecdotal.

While religion has been co-opted in many ways for power and political purposes, there is a reason almost every group of people around the world has had some kind of religious belief system. It's not just to explain the world around them. It's because we seek hope, meaning, and a feeling of connection to something bigger than ourselves.

There are many ways to achieve that, yes. But I am willing to bet that need for hope and meaning is hard-wired into our brains, and is doubtless one of the reasons for the achievements of homo sapiens sapiens.

It is a short and brutish life, and religion and spiritual practice are one way of guiding your inner state instead of leaving it to the mercy of events.

And every group develops its own language to help its members do this important survival task.

Religion is means to power and politics.Its not a disease... It like a "Matrix".Imagine a world without religion.....EU will have no problem with turkey I guess....Obama could use his full name then....Has religion achieved its objective as yet.... i dont think so..religion is rigidIs there a cure for this problem... or is there a "Neo" waiting to fight.The society should based on equality, fairness and kindness...I am sure every human is capable of understanding and behaving in appropriate way. religion will only put him or her in " matrix" state.Only way to achieve "nirvana" is not to be religious. atleast one less reason to wear cross, or study in religious based school or fund a holocaust...Is there a cure for this disease ?

I also don't see much value in this theory.159 religions in Brazil (I'm brazilian)? Brazil is mostly (over 70%) catholic. There are several "new" protestant religions, but those should not be counted as independent. To reach this number, I'm guessing one must consider every small group of natives isolated in the country, as well as many other religions coming from other small groups from Africa (Umbanda, Candomblé,...). These have only to do with migration, not with disease.

This seems to have been pseudo-science, not "proper" science: the researchers found what they wanted to find [you could say that they had a hypothesis and tested it, but that seems to me too generous on the basis of the article]; they could easily have found something quite different. Nevertheless, they may be right.But it is conventional wisdom, if not scientific fact, that genetic diversity is a protection against disease. This is held to account for the apparent sexual attraction between men and women of different races. Atheists, then, have healthier children even though they themselves might succumb to disease!

The logic seems to make sense although in this case we may be looking at the wrong data. As others have pointed out, most religions came about centuries ago. While biology isn't my specialty i would hazzard a guess that barring major climate changes, regions that are currently disease ridden would have been at the time these religions were created. bozzer: once again I am speaking from a limited knowledge base but as far as im aware disease limits cultures ability to develop (look at many of the African nations). If I'm miss understanding your definition of civilized, or if you have data showing otherwise please share.

this seems like very suspect research (or at least the interpretation of it) - have the authors controlled for how 'civillised' (for want of a better term) a society is? in general it seems that more civilised societies have less diversity in diseases and religion (e.g. because of technological progress and improved communication). if a society was equally civilised in other respects but had more diversity in disease and religion I might start to be convinced.Otherwise this sounds like a classic case of ignoring a third variable that both of the focal variables are correlated to.

Just another criticism:"the correlation between the number of religions in a place and how disease-ridden it is looks impressive"Prediction would say that multicultural metropolies of the developed world, like New York or Amsterdam would be very parasite ridden. They are not.Also, religions and diseases evolve at different time-scales. Most religions evolved millenia of centuries ago, while infectionus diseases spread quickly. E.g. most religions in Americas are old native religions. How would Native Americans predict that Europeans would bring new diseases? Colonialism spread many diseases, but diminished the number of religions (judging that most Europeans are Christians or Jews, but wiped out very many native cultures).

Correlation is not a proof of cause and effect. And it only shows that countries with many local religions tend to be poor. Authors' explanation is very stretchy to hopeless. It predicts no proselitising religions, or their members should die off after acquiring diseases from members of other religions. Selection should remove expensive temples, rituals and complications of belief systems. They are cost without benefit. There should be no drive to make one-religion countries. I'm sure open-minded readers can point more inconsistencies.In fact, religion, art, esthetic concept and many other higher values of humanity cannot be explained as products of natural selection. So, is the lack of rational benefit of religion a logical proof of God?

This theory may be in conflict with the fact that the two biggest religions, Islam and Christianity, are actually very universalist in their orientation. Far from separating people they are bent on imposing themselves on everybody around. But I admit this contradiction can be explained away somehow. The first religions seem to have been predominantly ethnic or clan based. Nevertheless there is certainly more to religion than protection against parasites and infectious deceases.

Lorem and grahamlaight:I think some careless staff at Economist.com just uploaded the wrong article. The right one is here:http://journals.royalsociety.org/content/500u4v5207hx3635/?p=f2810c954108489e85a147e23899c51e&pi=0"Assortative sociality, limited dispersal, infectious disease and the genesis of the global pattern of religion diversity"Clerical things aside, I would like to hear Richard Dawkins respond to this.

Regions with many diseases are poorer than others with fewer (Brazil v Canada). Poorer regions tend to have less well educated populations. The uneducated in turn tend to be more mistrustful of those that are not of their kind. That could explain the need of greater religious diversity.

"Years ago, without a knowledge of the nature of disease, this would probably be the most logical conclusion."

Logical conclusions are somewhat rare breed in the realm of religion. Very often logic and religious dogmas are mutually exclusive. Say in medieval Mongolia biggest sin was to urinate into flames of a campfire. Very few people would find any logic in it today. Chances are logic was not even required back then for ordinary Mongolian citizens to prevent them from committing the sin. Whether or not this religious restriction was anyhow related to any disease spreading is not known as well.

Interesting. For a long time I have wondered if disease and death didn't "prove" that a given religious view was correct. For example, if a given religion forbids sodomy and then a different, permissive population is decimated by disease, it would appear that God is punishing them and "prove" that the restrictive religion is correct. I'm thinking of Falwell's statements about AIDS as a recent example. If these contagions were limited to city-states (e.g. Sodom and Gomorrah) it would certainly seem that God had punished specific sinners, rather than a disease running its course in a closed environment. Years ago, without a knowledge of the nature of disease, this would probably be the most logical conclusion.

"Canada only has 15 religions?? Surely Vancouver must have 4x that many."

Chances are authors were including different subdivisons of Christianity in one category. In many cases even clerical personnel allows to play down distinctions. For example, a godparent for a Russian kid can be of Russian, Ukranian, Georgian, Armenian or Greek Orthodox Churches.

I feel I must inquire if the study linked in the sidebar of the article is indeed the correct one.I have read the full text and must point out that the word "religion" quite simply does not appear in it - instead it deals with the correlation of "collectivism" and "individualism" with the prevalence of pathogens. Collectivism in this sense implies a stronger connection with one's community and such traits as ethnocentrism and conformity, and while those features may be correlated with religion, I am unsure how they are correlated with religious diversity. One may hope that this is a case of accidentally omitting additional relevant research from the references and not one of inventing or twisting facts to fit a more exciting headline.

I am going to stir the pot for fun and say that the rational religion of science and technology ala Richard Dawkins, rather than irrational religions, has been the major cause of the new type of chronic diseases that we suffer from.What I am saying is that the modern combination of processed foods and modern alienated technology driven lifestyle are primary causative factors behind the rising epidemic of obesity, type 2 diabetes, heart disease, arthritis, depression etc.If we look at a virus like HIV we can hypothesise that it started from human to animal contact that increased as a result of technology. Certainly technology like vehicles and aircraft facilitated its spread. And I doubt whether it would be reasonable to suggest that the early victims of the disease - the gay community and intravenous drug users could be classified as religious.